667764 has 42 divisors (see below), whose sum is σ = 1759730. Its totient is φ = 221616.

The previous prime is 667753. The next prime is 667769. The reversal of 667764 is 467766.

It can be written as a sum of positive squares in only one way, i.e., 656100 + 11664 = 810^2 + 108^2 .

It is a Harshad number since it is a multiple of its sum of digits (36).

It is a congruent number.

It is an inconsummate number, since it does not exist a number n which divided by its sum of digits gives 667764.

It is not an unprimeable number, because it can be changed into a prime (667769) by changing a digit.

It is a polite number, since it can be written in 13 ways as a sum of consecutive naturals, for example, 2802 + ... + 3030.

2⁶⁶⁷⁷⁶⁴ is an apocalyptic number.

It is an amenable number.

It is a practical number, because each smaller number is the sum of distinct divisors of 667764, and also a Zumkeller number, because its divisors can be partitioned in two sets with the same sum (879865).

667764 is an abundant number, since it is smaller than the sum of its proper divisors (1091966).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

667764 is a wasteful number, since it uses less digits than its factorization.

667764 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 251 (or 234 counting only the distinct ones).

The product of its digits is 42336, while the sum is 36.

The square root of 667764 is about 817.1682813228. The cubic root of 667764 is about 87.4059506480.

It can be divided in two parts, 667 and 764, that added together give a triangular number (1431 = T₅₃).

The spelling of 667764 in words is "six hundred sixty-seven thousand, seven hundred sixty-four".